Linear solvation energy relationships. Part 4. Correlations with and limitations of the α scale of solvent hydrogen bond donor acidities
Linear solvation energy relationships. Part 4. Correlations with and limitations of the α scale of solvent hydrogen bond donor acidities
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线性溶剂化能关系第 4 部分：溶剂氢键供体酸度的 α 尺度的相关性和局限性。
DOI：
10.1039/p29790001723
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发表时间：
1979
期刊：
影响因子：
--
通讯作者：
M. J. Kamlet
中科院分区：
文献类型：
--
作者：
R. Taft;M. J. Kamlet
本文采用溶致变色比较法，修正和扩充了溶剂HBD（氢键供体）酸度α标度的数据库。结合溶剂极性的π* 标度，α标度通过以下形式的方程XYZ= XYZ 0 +sπ*+aα来合理化溶剂对许多化学性质和反应参数（XYZ）的影响。考虑的属性包括电子光谱数据，溶剂之间的转移自由能，19 F和31 P n.m.r.。位移和对数反应速率常数。结果表明，Dimroth的ET（30）和Kosower的Z标度，旨在作为溶剂极性的测量（即π*-当量），以及Gutmann的“受体数（AN）”标度，旨在作为溶剂亲电性的测量（即α-当量），实际上对应于π* 和α的线性组合。
The solvatochromic comparison method is employed to amend and expand the data base for the α scale of solvent HBD (hydrogen bond donor) acidities. In combination with the π* scale of solvent polarities, the α scale serves to rationalize solvent effects on a number of chemical properties and reaction parameters (XYZs) through equations of the form, XYZ=XYZ0+sπ*+aα. Properties considered include electronic spectral data, free energies of transfer between solvents, 19F and 31P n.m.r. shifts, and log reaction rate constants. It is shown that Dimroth's ET(30) and Kosower's Z scales, intended as measures of solvent polarity (i.e.π*-equivalent), and Gutmann's ‘Acceptor Number (AN)’ scale, intended as a measure of solvent electrophilicity (i.e.α-equivalent), correspond in fact to linear combinations of π* and α.